Bolthole Index

Franklin County, Washington

Building permits, zoning and septic rules in Franklin County, Washington

39Index Score / 100
#36 of 39 in Washington

Franklin County, Washington requires county-issued building permits and inspections for dwellings and most buildings before use or occupancy12. Franklin County Planning and Economic Development handles construction permitting and zoning in unincorporated areas, while Benton-Franklin Health District permits and inspects qualifying septic systems345.

At a glance

Building permit
Required for dwellings and most buildings before use or occupancy1
Zoning
Yes in unincorporated areas; confirm the parcel's district and standards46
Septic
Benton-Franklin Health District permits, oversees design and installation, and inspects covered systems57
Owner-builder
Exempt from contractor registration on your own property, but not from permits8
Permit fees
Published; building, plumbing and mechanical fees are due when the permit is issued9
RV or tiny-home living
Temporary occupancy requires a planning permit and approvals; RV parks require conditional-use approval1011
Road approach
County permit required in unincorporated areas for a structure valued at $25,000 or more12

Who to call

Building permits

Franklin County Planning and Economic Development Department

Building permits, inspections, zoning, land use permitting, long range planning, code enforcement, flood damage prevention, and outdoor burning regulations for unincorporated Franklin County

509-545-3521

planninginquiry@franklincountywa.gov

502 W Boeing Street, Pasco, WA 99301

Septic permits

Benton-Franklin Health District, Pasco Office

On-site sewage (septic) permits, design review, and inspections for Franklin County

509-547-9737

412 W. Clark Street, Pasco, WA 99301

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Off-grid gear

Going off-grid in Franklin County means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Franklin County, Washington?

Yes. Franklin County requires county-issued building permits and inspections for dwellings and most buildings before use or occupancy12. Permit submittals must follow the 2021 IRC, IBC and Energy Credit Code standards13. Franklin County publishes separate forms for residential work, additions, remodels, demolition, grading and several land-use reviews14. Building, plumbing and mechanical fees are paid when the permit is issued and can be estimated beforehand9. An owner working on their own property may qualify for Washington's contractor-registration exemption, but that exemption does not remove the building-permit requirement and does not apply when the work is for sale, demolition or lease8.

Who is the Franklin County building department, and how do you reach them?

The Franklin County Planning and Economic Development Department administers construction permitting and inspection, land-use permitting, long-range planning and code enforcement3. Its office is at 502 W Boeing Street in Pasco; call 509-545-3521 or email planninginquiry@franklincountywa.gov with building or zoning questions3. Ask which published building or planning application fits the work, whether grading or floodplain review is separate, and what inspections must be completed before occupancy14152. Franklin County requires the appropriate floodplain-development approval before work begins in a floodplain15.

Does Franklin County have zoning?

Yes. Franklin County applies its Zoning Ordinance in unincorporated areas; incorporated municipalities may administer their own land-use rules4. Confirm the parcel's district with Planning and Economic Development because setbacks, frontage, shoreline buffers and critical-area buffers can affect placement163. The available material does not provide a complete current list of districts or all dimensional standards17. Limited agricultural uses on parcels larger than 2.5 acres may qualify as permitted uses only in specified districts after site inspection and verification by the planning director; that is not a blanket exemption from building or land-use requirements18.

How do septic permits work in Franklin County?

Benton-Franklin Health District permits, oversees design and installation, and inspects on-site septic systems with wastewater flows below 3,500 gallons per day5197. Contact the district's Pasco office before fixing the house location or site plan20. About 41% of Franklin County soils rate free of severe limits for a conventional drain field, so do not assume a standard system will fit every parcel21. We could not confirm which alternative off-grid sanitation methods Franklin County accepts; ask Benton-Franklin Health District before planning anything other than an approved septic or sewer connection20.

Can you live in an RV or tiny home on your land in Franklin County?

Franklin County allows temporary occupancy of a mobile home, travel trailer, RV or fifth wheel for family hardship, while building a residence, or for farm family or farm labor, but a temporary permit from the planning department and health- and building-department approvals are required10. These permits generally run for six months and may be extended for one additional six-month period after conditional-use approval10. An RV park requires a special or conditional use permit, is limited to specified zoning districts, and needs at least four acres11. These rules do not establish general long-term RV living on any private parcel. We could not confirm a Franklin County rule for tiny-home occupancy; ask Planning and Economic Development whether the parcel's zoning allows the proposed home and what building, septic and land-use approvals apply3.

Building a home in Franklin County: the steps, in order

  1. Call Franklin County Planning and Economic Development at 509-545-3521 to confirm the zoning district, setbacks, frontage and required applications316.
  2. If the home will use septic, contact Benton-Franklin Health District at 509-547-9737 before fixing the site plan2019.
  3. Prepare the building submittal to the 2021 IRC, IBC and Energy Credit Code standards13.
  4. Obtain any separate grading or floodplain approval and, in unincorporated Franklin County, a road-approach permit for construction valued at $25,000 or more1512.
  5. Request a fee estimate; building, plumbing and mechanical fees are due when the permit is issued9.
  6. Complete the required building and septic inspections before use or occupancy27.

What to check before you buy land in Franklin County

Confirm the parcel's zoning district, setbacks and legal buildability with Franklin County Planning and Economic Development6163. Short plats and long plats are regulated in unincorporated Franklin County, so do not assume a large tract can be divided as proposed2223. Ask Benton-Franklin Health District about septic feasibility; roughly 41% of county soils rate free of severe limits for a conventional drain field21. Check floodplain status and road access before choosing a house site1512. We could not confirm a universal water or sewer connection rule or the exact private-well approval path, so ask the building and septic offices what applies to the parcel320. The median property-tax bill is about $2,638 per year, with an effective rate near 0.8%2425.

Watch-outs

  • Franklin County requires the appropriate permit before floodplain development begins15.
  • A temporary RV permit is not general permission for long-term RV living; the stated hardship, construction and farm-related paths require county and health approvals10.

Sources

  1. franklincountywa.gov, quoted and re-checked
  2. franklincountywa.gov, quoted and re-checked
  3. Franklin County Planning and Economic Development Department (franklincountywa.gov)
  4. Code Enforcement Program, quoted and re-checked
  5. On-Site Sewage, quoted and re-checked
  6. Franklin County GIS, quoted and re-checked
  7. On-Site Sewage, quoted and re-checked
  8. RCW 18.27.090 — Exemptions, quoted and re-checked
  9. Building Fees, quoted and re-checked
  10. Franklin County Code § 17.66.250 — Temporary use of a trailer, quoted and re-checked
  11. Franklin County Code § 17.64.030 — Conditional use permit required, quoted and re-checked
  12. New Residential Dwelling Application Packet, quoted and re-checked
  13. Application Forms, quoted and re-checked
  14. Application Forms, quoted and re-checked
  15. franklincountywa.gov, quoted and re-checked
  16. Property, quoted and re-checked
  17. Plans & Ordinances, quoted and re-checked
  18. Franklin County Code Title 17 text amendment document, quoted and re-checked
  19. On-Site Sewage, quoted and re-checked
  20. Benton-Franklin Health District, Pasco Office (bfhd.wa.gov)
  21. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  22. Current Planning, quoted and re-checked
  23. Plans & Ordinances, quoted and re-checked
  24. Median property tax bill: Bolthole Index county data
  25. Effective property tax rate: Bolthole Index county data

Written October 10, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

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Compared with neighboring counties

Like all 6 of its neighbors, Franklin County requires a building permit for a home.

RuleFranklin CountyWalla Walla CountyBenton CountyAdams CountyColumbia CountyGrant CountyGarfield County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsBenton-Franklin Health DistrictCounty Dept. of Community HealthBenton-Franklin Health DistrictCounty Health Dept.County Public HealthCounty Health DistrictCounty Public Health

County locator

Franklin County in Washington

39
County map
Franklin County highlighted among the Washington counties · colored by Index score

How Franklin County scores

Seclusion63100% ev.
Self-Sufficiency1592% ev.
Admin Boringness41100% ev.
Durability60100% ev.
Property Autonomy50100% ev.
Carry Cost72100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$423kTypical home
0.8%Property tax
$5,182Land / acre
9.6"Annual rain
19% of yrsSevere drought
15.3 / yr (+10.5)Mid-century 100°F days
41.2 daysMid-century dry spell
0.5" (+8.8%)Mid-century 1-day rain
1.15×Wildfire change factor
100%Forward climate coverage
$1,270Home insurance / yr
1.6% / yrInsurance growth
1.58%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
4,349People within 30 min
1,410,058People within 2 hr
8,431Radius comparison (15 mi)
79.8People / sq mi
7.5%Federal land
76.4%Land at 15% slope or less
40.8%Soils rated "not limited" for septic (strict USDA rating)
277,931 acWorkable land screen
4.2%Wooded land
52°FAvg temp

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Cities and towns in Franklin County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Kahlotus · Mesa

Answers from the rulebook for Franklin County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Franklin County rules

  • Building permitRequired

    Construction of dwellings and most buildings in Franklin County.

    • The cited page also states that grading, flood plain development, and other activities may require separate permits.
    • Not all parcels are legal buildable lots.
    “Construction of dwellings and most buildings in Franklin County require county-issued building permits and inspections prior to use or occupancy. The permitting process not only helps assure you that your proposed project is in conformance with applicable state construction codes, but also that it is consistent with other requirements regulating property divisions and uses such as setbacks, minimum frontage, potable water supply, and sewage disposal systems.”
    One more reviewed finding on this topic
    • Required — Dwellings and most buildings in Franklin County.
      “Construction of dwellings and most buildings in Franklin County require county-issued building permits and inspections prior to use or occupancy.”
  • Building code adoptedAdopted (with conditions)

    County building-permit submittals governed by Franklin County.

    • All permit submittals must be designed to the 2021 standards.

    building code standard: 2021 IRC, IBC, and Energy Credit Code

    “The 2021 IRC, IBC, and Energy Credit Code is now in effect!”
    One more reviewed finding on this topic
    • Adopted (with conditions) — County building permit submittals subject to Franklin County building regulations.
      “The 2021 IRC, IBC, and Energy Credit Code is now in effect! ALL Permit Submittals MUST be designed to the 2021 standards.”
  • InspectionsRequired

    Dwellings and most buildings in Franklin County before use or occupancy.

    • The source states the requirement for dwellings and most buildings, not every possible structure.
    “Construction of dwellings and most buildings in Franklin County require county-issued building permits and inspections prior to use or occupancy.”
    One more reviewed finding on this topic
    • Required — Dwellings and most buildings in Franklin County.
      “Construction of dwellings and most buildings in Franklin County require county-issued building permits and inspections prior to use or occupancy.”
  • Certificate of occupancyLimited

    Structures on lots or parcels within an approved subdivision.

    • The cited subdivision text is dated March 14, 2022 and is identified as a planning-review version.
    • The rule does not establish a countywide certificate-of-occupancy requirement for all structures.
    • Temporary contractor offices and temporary storage buildings are excepted.
    “No occupancy permit for a structure other than a temporary contractor's office or temporary storage building shall be issued for a structure on a lot or parcel within an approved subdivision prior to final inspection and approval of all required infrastructure and subdivision improvements which will serve such lot.”
  • County-wide zoningPresent (with conditions)

    Franklin County zoning regulation in unincorporated areas.

    • The county code-enforcement page expressly refers to the County Zoning Ordinance and zoning issues.
    • Incorporated municipalities may administer their own land-use regulations.
    “If a citizen of Franklin County suspects that there is a violation of the County Zoning Ordinance on a particular piece of property, it is necessary to fill out a "Request for Investigation" form that can be obtained from a Code Enforcement Officer in the Planning Department.”
    One more reviewed finding on this topic
    • Present (with conditions) — County zoning regulation administered for development proposals in unincorporated Franklin County.
      “The Franklin County Planning Department provides a variety of planning services to the citizens of the unincorporated areas of Franklin County. These services include the reviewing and processing of land use development proposals for conformance with the County's Comprehensive Plan and other County policies and regulations. In addition to the Comprehensive Plan, the Department administers the implementation of the County's Zoning and Subdivision Ordinances.”
  • Zoning districtsPublished (with conditions)

    Zoning districts and zoning-map information for unincorporated Franklin County.

    • The county publishes a planning map containing zoning information and lists a county Zoning Ordinance.
    • Specific district dimensional standards were not separately extracted in this run.
    “A map that includes information related to planning and building, such as zoning and urban growth areas.”
    One more reviewed finding on this topic
    • Partial — County zoning districts and zoning administration in unincorporated Franklin County.
      “13. Subdivision Ordinance 14. Zoning Ordinance”
  • Minimum lot sizeSpecified

    At least one Franklin County zoning district identified in the Title 17 planning-review document.

    • The cited numeric standard is district-specific and should not be generalized to every county parcel.
    • The source is dated March 14, 2022 and identified as a planning-review version.

    minimum lot area: 5000 square feet

    “In addition to applicable standards included in Chapter 17.66 and 17.72, the following dimensional standards apply: A. Minimum lot area: 5,000 square feet. B. Density: one dwelling per 5,000 square feet of lot area. C. Maximum lot coverage: 40 percent.”
  • SetbacksSpecified

    Property divisions and uses in unincorporated Franklin County, including applicable shoreline and critical-area situations.

    • The official page states that setback requirements regulate property divisions and uses.
    • The official page separately states that shoreline and critical-area regulations establish setbacks and buffer zones near regulated waters and wetlands.
    “The permitting process not only helps assure you that your proposed project is in conformance with applicable state construction codes, but also that it is consistent with other requirements regulating property divisions and uses such as setbacks, minimum frontage, potable water supply, and sewage disposal systems.”
  • Lot coverageSpecified

    At least one Franklin County zoning district identified in the Title 17 planning-review document.

    • The standard is district-specific.
    • The source is dated March 14, 2022 and identified as a planning-review version.

    maximum lot coverage: 40 percent

    “In addition to applicable standards included in Chapter 17.66 and 17.72, the following dimensional standards apply: A. Minimum lot area: 5,000 square feet. B. Density: one dwelling per 5,000 square feet of lot area. C. Maximum lot coverage: 40 percent.”
  • Living in an RVLimited

    Recreational vehicle parks in Franklin County zoning districts.

    • A recreational vehicle park requires a special/conditional use permit.
    • RV parks may be established only in C-1, C-2, C-3, CR, RC-1, RC-5, AP-20, and AP-40 zoning districts.
    • The minimum site area is four acres.
    • Within urban growth areas, the park must be within 2,000 feet of a state or interstate highway.
    • The owner, operator, and occupants must comply with permit conditions.

    minimum RV park site area: >= 4 acres · distance from highway within urban growth areas: <= 2000 feet (applies within urban growth areas)

    “The minimum site area of a park shall be four acres.”
    One more reviewed finding on this topic
    • Temporary only (with conditions) — Temporary occupancy of a mobile home, travel trailer, RV, or fifth wheel on a lot subject to Franklin County zoning.
      “The temporary use of a mobile home/trailer [...] may be allowed under the following cases, subject to securing a temporary mobile home/travel trailer permit”
  • Who permits septicLocal (with conditions)

    On-site septic systems in Benton-Franklin Health District service territory, including Franklin County.

    • The cited authority covers on-site septic systems with wastewater flows less than 3,500 gallons per day.
    • Washington State Department of Health rules are also listed as applicable resources.

    wastewater flow threshold: < 3500 gallons per day

    “The Benton-Franklin Health District is responsible for permitting, overseeing the design and installation and inspecting of on-site septic systems with wastewater flows less than 3,500 gallons per day.”
    One more reviewed finding on this topic
    • Local (with conditions) — On-site septic systems with wastewater flows less than 3,500 gallons per day in Franklin County's Benton-Franklin Health District service area.
      “The Benton-Franklin Health District is responsible for permitting”
  • Septic permitRequired

    Residential building applications requiring on-site sewage disposal in Franklin County.

    • The sewage disposal construction permit must be signed by a Health District official.
    • If located within a sewer service area, the requirement may be waived.
    • The Health District page states its permitting responsibility for systems with flows less than 3,500 gallons per day.

    wastewater flow: < 3500 gallons per day (Requirement may be waived if located within a sewer service area)

    “Sewage Disposal System Construction Permit from BFHD.”
    One more reviewed finding on this topic
    • Required — On-site septic systems with wastewater flows less than 3,500 gallons per day.
      “The Benton-Franklin Health District is responsible for permitting, overseeing the design and installation and inspecting of on-site septic systems with wastewater flows less than 3,500 gallons per day.”
  • Septic inspectionRequired

    On-site septic systems in Franklin County within the BFHD jurisdiction and below 3,500 gallons per day.

    • The BFHD program covers systems with wastewater flows less than 3,500 gallons per day.

    wastewater flow threshold: < 3500 gallons per day

    “The Benton-Franklin Health District is responsible for permitting, overseeing the design and installation and inspecting of on-site septic systems with wastewater flows less than 3,500 gallons per day.”
    One more reviewed finding on this topic
    • Required — On-site septic systems with wastewater flows less than 3,500 gallons per day.
      “The Benton-Franklin Health District is responsible for permitting, overseeing the design and installation and inspecting of on-site septic systems with wastewater flows less than 3,500 gallons per day.”
  • Agricultural exemptionConditional

    Limited agricultural uses in specified Franklin County zoning districts.

    • Agricultural uses may be considered permitted for parcels greater than 2.5 acres.
    • Site inspection and verification by the planning director are required.
    • The rule is district-specific and is not a blanket exemption from all permits or regulations.

    minimum parcel size: > 2.5 acres

    “Agricultural uses (limited) may be considered a permitted use (Section 17.18.020 of this chapter) upon site inspection and verification by the planning director for parcels of land greater than 2.5 acres in size;”
  • Subdividing landRegulated (with conditions)

    Subdivision and platting in unincorporated Franklin County.

    • The county publishes both short-plat and long-plat application forms and lists a Subdivision Ordinance.
    • Municipal subdivision rules may apply within incorporated cities.
    “Short Plat (Short Subdivision) (PDF) Subdivision (Long Plat) (PDF)”
    One more reviewed finding on this topic
    • Regulated (with conditions) — Short subdivisions, subdivisions, short plats, and long plats in unincorporated Franklin County.
      “In addition to the Comprehensive Plan, the Department administers the implementation of the County's Zoning and Subdivision Ordinances, Shoreline Master Program, Critical Area Ordinance, and the Washington State Environmental Policy Act (SEPA) relative to development proposals.”
  • Driveway accessLimited

    Road approach access for structures in unincorporated Franklin County.

    • A road approach permit is required for construction of any structure valued at or over $25,000.
    • Franklin County Public Works issues the permit in unincorporated areas; WSDOT applies off state routes/highways; the City of Kahlotus applies within its city limits.

    structure value threshold: >= 25000 USD

    “Required for the construction of any structure valued at or over $25,000”
  • Building in a floodplainLimited

    Development in flood plains or flood zones in Franklin County.

    • The county states that appropriate permits for flood plain development may be required.
    • The residential application packet requires floodplain/flood-zone information on the site plan.
    “appropriate permits for grading, flood plain development”
    One more reviewed finding on this topic
    • Required — Development in Franklin County floodplain areas.
      “Before commencing construction, be sure you have obtained the appropriate permits for grading, flood plain development, and other activities that may require a permit.”
  • Permit feesPublished (with conditions)

    Franklin County building, plumbing, and mechanical permit fees.

    • Fees are paid when the permit is issued.
    • Fees can be estimated before issuance.
    • The fee tables are based on February 2020 Building Valuation Data and are subject to amendment.

    fee payment timing: when permit is issued · valuation basis: February 2020 Building Valuation Data (Subject to amendment)

    “Building, plumbing and mechanical fees are not required to be paid until the time a permit is issued.”
    One more reviewed finding on this topic
    • Published (with conditions) — Franklin County building, plumbing, and mechanical permit fees.
      “Building, plumbing and mechanical fees are not required to be paid until the time a permit is issued. Fees can be estimated by the Building Division prior to the time of issuance.”
  • Permit processPublished (with conditions)

    Franklin County building and planning permit applications.

    • The county publishes separate building and planning forms, including residential, remodel, addition, demolition, grading, short-plat, long-plat, special-use, SEPA, shoreline, rezone, and variance forms.
    • All permit submittals must be designed to the 2021 standards.
    “The 2021 IRC, IBC, and Energy Credit Code is now in effect! ALL Permit Submittals MUST be designed to the 2021 standards.”

Washington rules that apply here

  • Owner-builder exemptionConditional

    An owner or other person performing construction-related contractor activities on the person's own property or personal residence under Washington contractor-registration law.

    • The exemption concerns registration provisions under chapter 18.27 RCW and does not itself eliminate applicable building, electrical, plumbing, mechanical, land-use, or inspection requirements.
    • For work on the person's own property, the exemption does not apply when the person performs contractor activities for the purpose of selling, demolishing, or leasing the property.
    • For an owner contracting with a registered contractor, the exemption does not apply to a person performing contractor activities to lease or sell improved property owned for less than twelve months.

    small-project contract threshold: < 500 USD (The threshold exemption does not apply when the work is part of a larger operation, contracts are divided to evade the chapter, or the person advertises as a contractor.)

    “The registration provisions of this chapter do not apply to: [...] (12) Any person working on his or her own property, whether occupied by him or her or not, and any person working on his or her personal residence, whether owned by him or her or not but this exemption shall not apply to any person who performs the activities of a contractor on his or her own property for the purpose of selling, demolishing, or leasing the property;”
    One more reviewed finding on this topic
    • Available (with conditions) — A person working on their own property or personal residence under Washington contractor-registration law.
      “The registration provisions of this chapter do not apply to: [...] (12) Any person working on his or her own property”
  • Minimum dwelling sizeSpecified

    Dwelling units regulated by Washington's state building code.

    • The rule specifies habitable-space and room-area minimums, not a zoning minimum lot or gross floor-area standard.
    • Kitchens are expressly excepted from the minimum floor-area requirement.
    • Efficiency dwelling units must comply with Sections 1208.1 through 1208.4 and must have a separate closet, required kitchen facilities, light and ventilation, and a separate bathroom as stated in the source.
    • The current rule text states WSR 23-23-102 was filed 11/15/23 and effective 3/16/24.

    minimum habitable space: >= 190 square feet · minimum area of at least one room: >= 120 square feet · minimum net floor area of sleeping units and other habitable rooms: >= 70 square feet (Kitchens are not required to be of a minimum floor area.)

    “1208.3 Dwelling unit size. Dwelling units shall have a minimum of 190 square feet (17.7 m 2) of habitable space. 1208.4 Room area. Every dwelling unit shall have not less than one room that shall have not less than 120 square feet (11.2 m 2) of net floor area. Sleeping units and other habitable rooms of a dwelling unit shall have a net floor area of not less than 70 square feet (6.5 m 2). EXCEPTION: Kitchens are not required to be of a minimum floor area.”
  • Building heightSpecified

    Buildings subject to Washington's state building code, with allowable height determined by occupancy classification and type of construction.

    • Table 504.3 is occupancy- and construction-type-specific.
    • The source states that Chapters 4 and 5 contain specific exceptions to the allowable height.
    • The table includes NS and UL entries; the source footnotes state that NS is only for evaluation of existing building height under the International Existing Building Code and that other entries have sprinkler-related conditions.

    allowable building height: occupancy-classification and construction-type specific values in Table 504.3 feet above grade plane (See Chapters 4 and 5 for specific exceptions.)

    “Allowable Building Height in Feet Above Grade Plane”
  • Tiny homesAllowed (with conditions)

    Occupancy and placement of tiny houses in Washington

    • A tiny house may be built on wheels and may not exceed 400 square feet including kitchen, bathroom, and sleeping/living area.
    • It must be built to the Washington State Building Code.
    • Approval depends on where it is built; local building-department requirements and permits apply to foundation, installation, and location.
    • A wheeled structure that is not a tiny house as described may instead be a recreational vehicle or park model.
    • A manufactured home, including a tiny manufactured home, requires consultation with the local building department regarding where it may be located.

    maximum area: <= 400 square feet

    “A tiny house is a dwelling that may be built on wheels and is no larger than 400 square feet, including a kitchen, bathroom, and sleeping/living area, and must be built to the Washington State Building Code. The approval process for a tiny house depends on where it's built.”
  • Manufactured homesLimited

    State statutory limits on county regulation of the placement or use of HUD-standard manufactured homes in Washington; site-specific occupancy remains subject to applicable local and state requirements.

    • The nondiscrimination and equal-siting rule applies to homes built to 42 U.S.C. Sec. 5401-5403 standards, as amended in 2000.
    • Except as provided in RCW 36.01.225(2), a county may require that a manufactured home be new.
    • Except as provided in RCW 36.01.225(2), a county may require a permanent foundation specified by the manufacturer and enclosure of the space from the bottom of the home to the ground with concrete or an approved concrete product, load bearing or decorative.
    • Except as provided in RCW 36.01.225(2), a county may require compliance with local design standards applicable to all other homes in the neighborhood.
    • Except as provided in RCW 36.01.225(2), a county may require thermal equivalence to the state energy code and all other requirements for a designated manufactured home under RCW 35.63.160.
    • A county may not restrict location in a manufactured/mobile home community legally in existence before June 12, 2008, based exclusively on the manufactured/mobile home's age or dimensions.
    • A county may not prohibit siting on an existing lot solely because existing separation and setback requirements regulating distance between homes are unmet.
    • A county may restrict location in a manufactured/mobile home community for other reasons, including failure to comply with fire, safety, other local ordinances, or state laws related to manufactured/mobile homes.
    • The statute does not override legally recorded covenants or deed restrictions of record and does not affect authority granted under chapter 43.22 RCW.

    community legal-existence date for age-or-dimensions protection: 2008-06-12 (Applies to manufactured/mobile home communities legally in existence before this date.)

    “A county may not adopt an ordinance that has the effect, directly or indirectly, of discriminating against consumers' choices in the placement or use of a home in such a manner that is not equally applicable to all homes. Homes built to 42 U.S.C. Sec. 5401-5403 standards (as amended in 2000) must be regulated for the purposes of siting in the same manner as site built homes, factory built homes, or homes built to any other state construction or local design standard.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units in portions of Washington cities, towns, and counties located within designated urban growth areas and subject to the Growth Management Act requirements

    • Cities and counties planning under the chapter must adopt or amend ordinances and development, zoning, and other official controls to implement the statutory requirements.
    • The requirements apply only in portions of towns, cities, and counties within designated urban growth areas.
    • Local governments may still apply public-health, safety, building-code, environmental-permitting, on-site-wastewater, and generally applicable development regulations.
    • Local governments may restrict or prohibit ADUs where development is restricted because of on-site sewage infrastructure, critical areas, or other unsuitable physical characteristics.
    • Under RCW 36.70A.681, at least two ADUs must be allowed on qualifying lots in configurations specified by statute, subject to listed exceptions and limitations.
    • The statutory requirements do not apply to lots designated with critical areas or buffers, or to specified impaired or threatened potable-water-reservoir watersheds.

    minimum ADUs in qualifying configurations: >= 2 accessory dwelling units per qualifying lot (Applies to lots in all zoning districts within an urban growth area that allow single-family homes, subject to statutory exceptions.)

    “The city or county must allow at least two accessory dwelling units on all lots that are located in all zoning districts within an urban growth area that allow for single-family homes in the following configurations:”
  • Well permitLimited

    Groundwater wells and groundwater uses statewide under Washington's water-right permit exemption.

    • Domestic use is exempt up to 5,000 gallons per day.
    • Industrial use is exempt up to 5,000 gallons per day.
    • Lawn or garden irrigation is exempt only for a half-acre or less.
    • Stockwater is exempt.
    • Only one permit-exempt use of each type is allowed for any one project, regardless of project size.
    • Withdrawals from multiple wells for one project are aggregated toward the exemption limits.
    • Local governments and other laws and rules may impose additional requirements and limits.
    • Use in excess of the listed amounts, use for other purposes, or use from a surface-water source requires applying for and receiving a water-right permit.
    • Before drilling, a notice of intent must be submitted to Ecology 72 hours before drilling starts; the NOI is not itself a permit or approval to use water.
    • Permit-exempt uses remain subject to state water law, including possible restrictions relating to senior water rights and Streamflow Restoration Act requirements.

    domestic groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · industrial groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · lawn or garden irrigation exemption: <= 0.5 acre (For lawn or garden irrigation.) · well construction notice: 72 hours before drilling (Notice of intent is not a permit, certificate, or water-right application.)

    “The groundwater permit exemption allows for four small uses of groundwater without a water right permit: Domestic uses of up to 5,000 gallons per day Industrial uses of up to 5,000 gallons per day Irrigation of a lawn or garden, a half-acre or less in size Stockwater”
  • Mandatory utility hookupConditional

    Existing OSS failures and certain new developments statewide when public sewer service and applicable local requirements exist.

    • For an existing OSS failure within a sewer utility service area, the local health officer must require public-sewer connection if the sewer utility allows connection and adequate service is available within 200 feet measured along the usual or most feasible access route.
    • For an OSS repaired under Table X, connection is required when the local health officer deems it necessary to protect public health, adequate public sewer becomes available within 200 feet under the stated measurement rule, and the sewer utility allows connection.
    • Local boards of health may require new development to connect to protect public health.
    • Local boards of health shall require connection for new development or a development with a failing OSS when required by the comprehensive land use plan or development regulations.
    • The rule was filed March 1, 2024, and became effective April 1, 2025.

    public sewer availability distance: <= 200 feet (Measured from the existing building-drain/building-sewer connection, or where no building drain exists, from where the sewer line begins, along the usual or most feasible route of access.)

    “(b) Require connection to a public sewer system if the sewer utility allows the connection and has adequate public sewer services available within 200 feet from where the existing building drain connects to the existing building sewer, or where no building drain exists, within 200 feet from where the sewer line begins, as measured along the usual or most feasible route of access.”
  • Campground & park staysLimited

    Recreational vehicles in the context of Washington's manufactured/mobile-home community statutes

    • The rule defines an RV as temporary and transient living quarters.
    • The RV is not occupied as a primary residence.
    • The RV is not immobilized or permanently affixed to a manufactured/mobile home lot.
    • This claim does not establish general statewide siting permission on private land; local land-use and building rules may apply.
    “(12) "Recreational vehicle" means a travel trailer, motor home, truck camper, or camping trailer that is primarily designed and used as temporary living quarters, is either self-propelled or mounted on or drawn by another vehicle, is transient, is not occupied as a primary residence, and is not immobilized or permanently affixed to a manufactured/mobile home lot.”
    One more reviewed finding on this topic
    • Limited — Camping and temporary occupancy in Washington State Parks facilities
      “The maximum length of stay shall be no more than 10 nights in one park within a 30-day period. Total nights stayed by the same camping party must not exceed 90 nights per calendar year in all state parks. These limitations shall not apply to those individuals who meet the qualifications of WAC 352-32-280 and 352-32-285.”
  • county zoning authorityGeneral

    Washington counties adopting zoning and related official controls for county jurisdiction, including unincorporated areas.

    • A county must create a planning agency as authorized in RCW 36.70.030 and RCW 36.70.040 before engaging in the chapter's planning program.
    • Zoning maps may be adopted only for areas covered by a comprehensive plan containing at least a land use element and a circulation element.
    • Zoning regulations may address land uses, building location and dimensions, yards and open spaces, population density, lot coverage, parking, and minimum gross floor area requirements for single-family detached dwellings.
    • The cited enabling provisions do not state a population threshold, named-county limitation, or special geographic limitation.
    “Any board, by ordinance, may establish classifications, within each of which, specific controls are identified, and which will regulate:”
    One more reviewed finding on this topic
    • General — Washington counties may plan and adopt zoning and other official controls for county land, including unincorporated areas, through their boards and planning agencies.
      “Such official controls may include, but are not limited to, ordinances establishing zoning, subdivision control, platting, and adoption of detailed maps.”
  • county building authorityGeneral

    Washington counties requiring and enforcing building permits and adopting amendments to the state building code for residential construction within county jurisdiction, including unincorporated areas.

    • The state building code must be enforced by counties and cities within their jurisdictional boundaries.
    • A county without a building department must contract with another county, city, or approved inspection agency for enforcement.
    • County amendments may not diminish the minimum performance standards and objectives of the state building code.
    • Residential-building amendments are subject to approval by the state building code council under RCW 19.27.074(1)(b), except as provided by statute.
    • The building-permit definition incorporates exemptions in International Building Code section 105.2 and International Residential Code section R105.2.
    • Counties may adopt permit exemptions for certain specified R-3 or M-1 construction or alteration with total fair market value not exceeding $1,500, but the exemption does not remove substantive code standards.

    permit-exemption fair-market-value ceiling: <= 1500 USD (Applies only to certain construction or alteration of group R, division 3, or group M, division 1 occupancies under RCW 19.27.060(7); substantive code standards still apply.)

    “The state building code required by this chapter shall be enforced by the counties and cities. Any county or city not having a building department shall contract with another county, city, or inspection agency approved by the county or city for enforcement of the state building code within its jurisdictional boundaries.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Local zoning — Aggregate zoning administration across Franklin County, including incorporated municipalities and unincorporated areas.
  • Camping on your land — Temporary camping on private land in unincorporated Franklin County.
  • Off-grid sanitation — Off-grid sanitation and non-septic wastewater treatment in Franklin County.
  • Short-term rentals — Short-term rentals in unincorporated Franklin County.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Water rights & wells in Franklin County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from Washington’s water agency.

Over-appropriated / declining

The aquifer here is over-appropriated and declining. A domestic well is usually still permit-exempt, but long-term supply is a genuine risk.

Household wellExempt up to a limit

RCW 90.44.050 exempts up to 5,000 gpd for domestic use, but the 2018 Streamflow Restoration Act caps NEW permit-exempt domestic wells at 3,000 gpd/connection in some basins and 950 gpd (350 gpd indoor in drought) in others, and new post-2020 wells in the adjudicating Nooksack basin are limited to ~500 gpd indoor.

Limit: 5,000 gpd base (RCW 90.44.050); capped to 3,000 or 950 gpd/connection in streamflow-restoration basins; ~500 gpd indoor for new Nooksack wells

Washington Dept of Ecology — Groundwater permit exemption ↗
  • Odessa Subarea (deep basalt aquifer decline)partial of county

    Columbia Basin deep basalt aquifer severely depleted (some wells ~2,400 ft, hot/high-sodium); Ecology's response is a Columbia River surface-water replacement program rather than a formal closure, but new large groundwater supply is practically unavailable.

    WA Dept of Ecology ↗

Hybrid state (appropriation + riparian). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the Washington state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in Franklin County, Washington

Is Franklin County a good place to live off-grid or homestead?

Franklin County scores 39/100 on the Bolthole Index, a marginal county profile. Its strengths: manageable long-term carry cost and sparse surroundings — about 4,349 people within a 30-minute drive. Watch-outs: weak self-sufficiency basics: only 9.6″ of rain a year and more administrative friction around building and land use.

Do you need a building permit in Franklin County, Washington?

Franklin County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Benton-Franklin Health District. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

Can you live in an RV or tiny home on your land in Franklin County?

Living in an RV on your own land in Franklin County is allowed on a temporary basis only: Temporary occupancy of a mobile home, travel trailer, RV, or fifth wheel on a lot subject to Franklin County zoning. A temporary mobile home/travel trailer permit from the planning department is required. During family hardship, the trailer is subject to Benton-Franklin Health District and county building department approval and the permit expires after six months. A tiny home is allowed. Confirm with the county before relying on it.

How much does land cost in Franklin County, Washington?

Land in Franklin County runs about $5,182 per acre, based on the latest county data.

What is the water situation in Franklin County?

Franklin County gets about 9.6" of rain a year, with severe drought in roughly 19% of years. On water rights, Franklin County lies in the Odessa Subarea (deep basalt aquifer decline) — Columbia Basin deep basalt aquifer severely depleted (some wells ~2,400 ft, hot/high-sodium); Ecology's response is a Columbia River surface-water replacement program rather than a formal closure, but new large groundwater supply is practically unavailable..

How remote is Franklin County?

A representative private-land location has about 4,349 people within a 30-minute drive and 1,410,058 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How Franklin compares in Washington

Compare side-by-side →See all 39 Washington counties ranked →